John Mellencamp & Meg Ryan: Look Who's Dating!

On a chilly morning two days after New Year's, Meg Ryan and a new boyfriend kicked off 2011 with hot coffee and warm kisses at Espresso Love, one of her favorite hangouts on Martha's Vineyard. Although the low-key locals tried not to pay attention, they couldn't help but notice when her pompadoured beau took off his shades-and revealed he was none other than rocker John Mellencamp. "They were kissing each other and giggling the whole time," says an eyewitness. "She looked really happy to be with him. All smiles."

The surprise romance between the movie star and the heartland musician famous for such hits as "Hurts So Good" and "Jack & Diane" emerged just days after Mellencamp, 59, announced a separation from his wife of 18 years, Elaine, 41, a model and mom of his two youngest kids, Hud, 16, and Speck, 15. (Mellencamp has three older kids from two previous marriages.) The couple "are proud of their 20 years together," Mellencamp's rep said in a statement, "but have decided to call it a day." A source close to Ryan says she started dating Mellencamp just seven weeks ago. "There's no drama," says the source. "He was separated from his wife months before they got involved. He didn't leave his wife for Meg." According to another source, the two met at a party, and Mellencamp asked Ryan to help narrate a musical he's recording, Ghost Brothers of Darkland County. "She didn't know him well before he and Elaine broke up," says the Ryan source.

With her own marital drama long in the past, Ryan, 49, who weathered a public split in 2000 from actor Dennis Quaid (with whom she has a son, Jack Henry, 18), has kept a low profile in recent years. Last seen onscreen in 2009's Serious Moonlight, she prefers to spend time with her son and daughter Daisy, 6, at their homes in Manhattan, Martha's Vineyard and Los Angeles. Ryan has said Quaid was unfaithful to her (which Quaid has characterized as a "rewrite" of their history), though her romance with Russell Crowe as her marriage ended was what captured the headlines. "My time as a scarlet woman was really interesting," she told INSTYLE in 2008. "As painful as it was, it was also incredibly liberating."

The Mellencamp split surprised friends who thought the longtime couple had defied the odds. Before meeting Elaine, the rowdy rocker (who has sold more than 40 million albums) had a penchant for wild nights and womanizing. "In the '80s I lived like an animal," he told INSTYLE in 1996. All that changed in 1991 when Mellencamp met the willowy supermodel Elaine Irwin, hired to appear in the video for his single "Get a Leg Up." Within weeks of their first date, she joined him on tour-and they wed the following year. Elaine, a '90s cover star who has modeled for Ralph Lauren, Calvin Klein and Almay, appeared to tame Mellencamp's wild streak. By all accounts the pair were devoted to family life on a 56-acre estate outside Bloomington, Ind., not far from where Mellencamp grew up. "Elaine has taken good care of John since he had a heart attack a few years ago," says a friend. The two plan to stay in Indiana, where, his rep says, "they will continue to raise their children."

Meanwhile, as Mellencamp once crooned, life goes on. He and Ryan, who will soon start shooting Lives of the Saints, a drama with 50 Cent, were spotted later on Jan. 3 shopping for groceries near her Manhattan home. She's taking her new relationship day by day. "It's not like they're getting married," says the Ryan source. "They just started dating."